Interesting discussion
I thought the MEL mentioned around 170deg per hour at 20deg OAT.
Through experience, that does seem about right.
Another discussion worth having is if they cool faster (without fans) with brakes on or off...
I believe it is faster with brakes on due to better heat sink. What exactly is the point of releasing carbon brakes when parked?
Brake fans are over-used by the many pilots who think brakes must be stone cold at push back. Whereas I understand carbon brakes are much more efficient once warmed up. So why does FCOM state switching brake fans on as soon as one reaches 100deg?